天津两种城市绿地土壤微生物与土壤呼吸特征

Soil microorganism and soil respiration characteristics of two kinds urban green space in Tianjin

对天津两种城市绿地国槐梨树林和国槐银杏林在6月、7月、8月土壤碳排放速率和土壤微生物数量进行测定,旨在深入了解土壤呼吸速率动态变化特征及其影响因子。结果表明,两种城市绿地土壤呼吸昼夜变化明显,土壤碳排放量白天大于夜间,且白天变异幅度比夜间大,观测期国槐梨树林和国槐银杏林土壤呼吸速率变异幅度分别为4.01和4.76,月均最大值均出现在8月;国槐梨树林和国槐银杏林土壤呼吸速率均值分别是2.01、1.94μmol/(m^2·s),表明国槐梨树林比国槐银杏林土壤碳排放量大;两种城市绿地土壤微生物数量表现为国槐梨树林>国槐银杏林,土壤细菌与土壤呼吸速率之间呈极显著正相关,土壤放线菌和真菌与土壤呼吸速率间呈显著正相关。

Soil carbon emission rates and soil microbial populations of two urban green space in Tianjin Sophora japonica Linn.-Pyrus i, f. woods and Sophora japonica Linn.-Ginkgo biloba L. woods were determined in June, July and August to determine soil respiration dynamics and its influencing factors. The results showed that day and night variation of soil respiration in two types of urban green spaces was obvious. Soil carbon emission was greater during the daytime than at night, and the daytime variation range was greater than that at night. During the observation period, the soil respiration rate variation of Sophora japonica Linn.-Pyrus i, f. woods was 4.01, and the soil respiration rate variation of Sophora japonica Linn.-Ginkgo biloba L. woods was 4.76, and the average monthly maximum occurred in August. The average soil respiration rates of Sophora japonica Linn.-Pyrus i, f. woods and Sophora japonica Linn.-Ginkgo biloba L. woods were 2.01 and 1.94 μmol/(m2·s), respectively. This indicated that Sinkgo japonica Linn.-Pyrus i, f. woods had a higher carbon emission than Sophora japonica Linn.-Ginkgo biloba L. woods. The total amount of soil microbes was greater in Sophora japonica Linn.-Pyrus i, f. woods.There was extremely obvious correlation between the seasonal changes of soil respiration rate and the number of soil bacterium.Soil respiration rate were significantly positive to actinomycetes and fungi.